Within the packaging industry, use is often made of a packaging material with a core of paper or cardboard laminated with thermoplastic and possibly a metal foil, e.g. aluminium foil, for the manufacture of single-use disposable packages or cartons for milk, juice or the like. The package is formed from a continuous material web or a material sheet. From, for example, a web, parallelepipedic packages are produced by uniting the longitudinal edges of the web with one another in a longitudinal overlap seam or joint to form a tube. The tube is filled with its intended contents and divided into closed packaging units by repeated transverse seals of the tube. In such instance, cushion-like packaging blanks are obtained which are thereafter finally formed into parallelepipedic packages.
In order to gain access to the contents of the package in a simple manner, some form of opening arrangement is required. In this instance, it is previously known in the art to inlay a tearing strip into one of the transverse sealing seams. Such an opening arrangement is described, for example in Swedish Patent Application No. S-9002640-2. By providing the packaging container with such an opening strip, there will be obtained an opening arrangement which, with a simple manual operation, opens the package and at the same time forms a part of the upper portion of the package into a pouring spout.
Such opening strips are often manufactured from a laminated plastic material in which one of the layers is cohesively broken upon so that a part of the opening strip is left in place on the inside of the packaging material. This is to prevent the packaging material from delaminating so that the inner layer of paper or cardboard is exposed to the liquid contents. However, it has been found that in the initial stage of the opening procedure, a certain delamination of the packaging material may take place with the above-described type of tearing strip.